Browse Prior Art Database

Three-Axes Wrist Drive

IP.com Disclosure Number: IPCOM000044479D
Original Publication Date: 1984-Dec-01
Included in the Prior Art Database: 2005-Feb-06
Document File: 2 page(s) / 65K

Publishing Venue

IBM

Related People

Barenboim, M: AUTHOR [+2]

Abstract

This article describes a compact three-degrees-of-freedom wrist drive for a clean room robot having three separate drives packaged in a modular fashion. This structure provides a compact circular drive geometry, high ratios and torque capabilities, and flex spline gears which have small backlash tolerances eliminating the need of anti-backlash gears. The wrist drive disclosed herein consists of 3 separate drives, namely, roll, pitch and yaw, and are packaged in modular fashion, as illustrated in Fig. 1. This allows individual selection of only the required number of motions for a given job. Each drive has a mounting surface for the attachment of additional drives or for the attachment of the end effector (gripper). The selected wrist arm is attached to a robot arm, as shown in Fig. 2.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Three-Axes Wrist Drive

This article describes a compact three-degrees-of-freedom wrist drive for a clean room robot having three separate drives packaged in a modular fashion. This structure provides a compact circular drive geometry, high ratios and torque capabilities, and flex spline gears which have small backlash tolerances eliminating the need of anti-backlash gears. The wrist drive disclosed herein consists of 3 separate drives, namely, roll, pitch and yaw, and are packaged in modular fashion, as illustrated in Fig. 1. This allows individual selection of only the required number of motions for a given job. Each drive has a mounting surface for the attachment of additional drives or for the attachment of the end effector (gripper). The selected wrist arm is attached to a robot arm, as shown in Fig. 2. All drives are equipped with a frameless 24 VDC high torque motor. The wrist housing provides the motor frame. Also enclosed in this housing is a high ratio (110:1) gear drive, called a harmonic drive. All drives are a closed-loop system with precision potentiometers for positional feedback. They are also contained in the wrist drive housings. The potentiometers are a conductive plastic dual-track drum-type design of maximum diameter for excellent resolution. A cam-actuated limit switch is included to provide a hard stop in the event of over-travel.

1

Page 2 of 2

2

[This page contains 6 pictures or other non-text objects]